TEHRAN, Iran (CNN) -- Iran's reformist former President Mohammad Khatami Sunday blasted the trials of people arrested in demonstrations as an "insult" to Iran and Islam.

Former Iranian President Mohammad Khatami says the trials of election protesters are damaging.

"Such play-acting ... damages the system and reduces public trust," he said in a statement provided by his office.

Nearly 100 Iranians arrested in the aftermath of the disputed June 12 presidential elections went on trial Saturday, two Iranian news agencies reported. In addition, another 10 people went on trial Sunday, according to Iran's government-funded Press TV, citing the Iranian Students News Agency (ISNA).

But Khatami said the trials were unconstitutional, contrary to "the law and the rights of citizens."

The real crimes had been committed by the authorities, he said.

He condemned "the atrocities committed at certain detention centers as well as those committed during arrests which, in some cases, resulted in murder."

He dismissed the reported confessions of the accused, as did another influential ex-president, Ali Akhbar Hashemi Rafsanjani, according to Iran's government-funded Press TV.

Among the nearly 100 defendants are several members of the reformist Mosharekat Party and a member of the central committee of the Kargozaran Party, which is close to Rafsanjani, the semi-official FARS news agency reported.

On Sunday, "10 other suspects were put on trial in a closed court session," ISNA quoted a judiciary official as saying, according to Press TV.

Don't Miss

A member of parliament's special committee for monitoring the condition of detainees complained Saturday that the trials began without the committee's knowledge.

"We were given no information," said Ghodratollah Alikhani, a member of the committee, according to the semi-official ILNA news agency. "Judiciary officials did not tell us anything about these trials."

He added: "The office of Tehran's prosecutor had earlier said that the court would try a number of people arrested for street demonstrations, but instead reformist activists are being tried."

At the same time Iran was trying the detainees, it released thousands of other prisoners after Supreme Leader Ayatollah Ali Khamenei pardoned them or commuted their prison terms, FNA reported Saturday.

"Forty percent of the country's inmates, who account for around 68,000 people, were liable to the amnesty," Mohammad Ali Zanjirei, a top official with the State Prisons Organization, told FNA.

He said 17,000 out of the 68,000 inmates were freed, and the rest will see their prison terms commuted or be granted leaves in the final months of their sentences.

The idea was originally proposed by Judiciary Chief Ayatollah Seyed Mahmoud Hashemi Shahroudi, FNA reported. Khamenei made the amnesty on the feast of Mab'ath, which marks assignment of the Prophet Mohammad to prophethood.

An Iranian legislator promised this week that the majority of the roughly 300 detainees arrested during post-election violence will be set free in coming days.